I am having hard time lately on my two Sabayon machines, one nVidia Ti 560 based, other Intel HD + nVidia 650M based, both with KDE.
On my desktop (nVidia Ti 560), I can't run certain accelerated apps, like Celestia.
On my notebook (ntel HD + nVidia 650M) I have weird tooltips in KDE, Rigo looks scrambled and I can't use it, only the command line instead. I think nVidia is never used. Plus, a second monitor never works (although I see a desktop on it, I can never reach it with a mouse pointer or other ways).

After some tests, I have observed one thing: I must reinstall bbswitch and bumblebee after each system upgrade in order to have a correct rendering in KDE and Rigo (not all GTK-based apps behave this way, I don't use many, so I can't tell if there's really a connection). I've tried bumblebee or bbswitch alone, but it is not enough.

I had the same problem on my old Nvidia Quadro with nvidia drivers-387*... and I didn't try to update drivers on my new laptop (Optimus)... I emerged 390.12 version from Gentoo repositories. Everything is working ok. ... Install kernel sources ("emerge" accept sabayon-sources) etc. ... Remove all "userspaces"... In all newer drivers (after 384*) the userspace is integrated inside (Gentoo). Probably it is our devs fault (forgotten userspaces)...

Last edited by gentmixer on Mon Feb 26, 2018 20:52, edited 2 times in total.

At last! With VLC 3.0 the crash is solved! Still, nvidia drivers or card initialization don't work, as I have to log in once, log out, log in again in KDE in order to work properly on the Optimus-based computer. And Celestia still does not find the nvidia driver libs unless I add the path to them to a launching batch.